[SOLVED] How to make changes to a dictionary persistent?

How to make changes to a dictionary persistent?

I'm trying to make small app that would calculate charge weight based on stored dict of materials/concentrations.
From time to time the dict needs to be updated and stored for future use.

Below snippet asks a user to provide new values for the dict and then updates it.

baseDict={'a':10, 'b':20, 'c':30, 'd':40}
def updateDict(key, value):
    temp = {key : value}
    baseDict.update(temp)
    return baseDict

key = str(input('Enter key\n'))
value = input('Enter value\n')
baseDict = updateDict(key, value)

The problem is that when the shell is re-started, the baseDict returns to the original values.
I found solutions for similar question from ~ 2010, but they use Pickle, shelve, JSON to store/retrieve the dict in a separate file and load it every time the code is run.

I'm planning to turn the code into a small .exe file to be ran on a py-less computer.
Any suggestions on how to make baseDict stay updated in such environment would be greatly appreciated.

Thank you!

Solution

Using json or pickle is better than saving plaintext and ast.literal_evaling it. I would recommend json:

For json, first run this once:

import json

with open('baseDict.json', 'w') as f:
    json.dump({'a':10, 'b':20, 'c':30, 'd':40}, f)

Then:

import json

with open('baseDict.json','r') as f:
    baseDict = json.load(f)

# your code

with open('baseDict.json', 'w') as f:
    json.dump(baseDict, f)

See here for why json is better than ast.literal_eval.